Evolution of flood flows in Upper Niger and Delta (West Africa)

Résumé

Climate change and the resurgence of floods are realities widely recognized today in the scientific community. Nevertheless, the impact of climate change on hydrological extremes is difficult to observe and predict. The objective of this study is to provide elements of response to the evolution of flood flows in Upper Niger and the Niger Delta during the period 1960-2012. To achieve this objective, the series of 30 hydrological stations were analyzed using statistical tests. The results show a significant decrease in floods in the majority of stations. In addition, the observed break-up period is between 1969-1971. The changes observed in the extreme hydrological series are not only due to the decrease in rainfall but also to other reasons. These include human activities on the basin (construction of hydraulic structures and agro pastoral developments), a change in the method of data acquisition that can cause breaks in the series.